It’s the same for the Decoy Plasmid - another ability we’ve seen in plenty of other games. But here you can place it on a barrel to trick melee Splicers into beating their way to a firey death. If they’re packing heat, set it front of a Big Daddy and see what happens. Our favorite was to place it just before vanishing with an Invisibility Tonic, then get bonus Research points for all the multiple-subject action shots we took of them beating the holographic hell out of my creepy doppelganger.

The richness of simulation is continually surprising, and the variety of absurd brutality that emerges from it is one of the three big reasons that BioShock is essential. Even when you’re not carefully tinkering with it to create deathtraps, it serves as a catalyst for the screeching, brutal chaos of combat. These are gallingly visceral fights. There’s something tangibly unkind about setting someone alight, then clotheslining them with a five-kilo bloodstained wrench as they scream past you towards water.

If you’re worrying about the dreaded taint of consolification, by the way, don’t. It’s clear that the PC team at Irrational are every bit as platform-snobbish as us. There’s a PC-only options menu that lets you turn off the quest compass guiding you to your next objective, disable the golden sheen on mission-critical items, and as for auto-aiming, it isn’t even an option unless you plug in a 360 pad.

Also exclusive to this edition is a magnificently intricate PC-only quick-switch menu. Because you can have 19 different weapon ammo types on top of your six Plasmids at any given time, using the mouse wheel can get fiddly. So there’s also a key you can hold down to pause the game and pick any one of those 25 modes of attack with a single click. Hacking, too, has been designed differently for the PC to make best use of the mouse - it’s quicker, slicker and less frustrating than the sluggish Xbox controls.

The final geekily gratifying thing about the PC version is how well it runs. It was dazzlingly beautiful and hitchlessly smooth on a machine with an Athlon X2 5200 and a single entry-level GeForce 8800 - running DirectX 9. And this was at 1600x900 on max settings.

But you don’t care about that. You want to know about the Big Daddies. Those diving-suited ogres have become the poster-boys of BioShock, but they’re less central to the game than we’ve been led to believe. You could complete it without ever attacking one. Each Big Daddy guards one Little Sister - a family tree only MC Escher could draw - and their relationship is bizarre and compelling to watch. Sometimes the girl will turn sulkily away from her giant friend; he’ll nudge her gently a few times for forgiveness, then offer her his enormous metal hand. She’ll turn and take it gently, bowing a little, and he pats her tiny head very, very carefully.